# Measurement of the $^{235}$U(n, f) cross section relative to the $^{6}$Li(n, t) and $^{10}$B(n, α) standards from thermal to 170 keV neutron energy range at n_TOF

Amaducci, S.; Cosentino, L.; Barbagallo, M.; Colonna, N.; Mengoni, A.; Massimi, C.; Lo Meo, S.; Finocchiaro, P.; Aberle, O.; Andrzejewski, J.; Audouin, L.; Bacak, M.; Balibrea, J.; Bečvář, F.; Berthoumieux, E.; Billowes, J.; Bosnar, D.; Brown, A.; Caamaño, M.; Calviño, F.; ... mehr

##### Abstract:
The$^{235}$U(n, f ) cross section was measured at n_TOF relative to $^{6}$Li(n, t) and $^{10}$B(n,α) , with high resolution ( L=183.49(2) m) and in a wide energy range (25meV-170keV) with 1.5% systematic uncertainty, making use of a stack of six samples and six silicon detectors placed in the neutron beam. This allowed us to make a direct comparison of the yields of the$^{235}$U(n, f ) and of the two reference reactions under the same experimental conditions, and taking into account the forward/backward emission asymmetry. A hint of an anomaly in the 10-30keV neutron energy range had been previously observed in other experiments, indicating a cross section systematically lower by several percent relative to major evaluations. The present results indicate that the cross section in the 9-18keV neutron energy range is indeed overestimated by almost 5% in the recently released evaluated data files ENDF/B-VIII.0 and JEFF3.3, as a consequence of a 7% overestimate in a single GMA node in the IAEA reference file. Furthermore, these new high-resolution data confirm the existence of resonance-like structures in the keV neutron energy region. The results here reported may lead to a reduction of the uncertainty in the 1-100keV neutron energy region. ... mehr

 Zugehörige Institution(en) am KIT Institut für Kernphysik (IKP) Publikationstyp Zeitschriftenaufsatz Publikationsjahr 2019 Sprache Englisch Identifikator ISSN: 0939-7922, 1431-5831, 1434-6001, 1434-601X KITopen-ID: 1000097261 HGF-Programm 51.03.04 (POF III, LK 01) Kosmische Strahlung Technologien Erschienen in The European physical journal / A Verlag Springer Verlag Band 55 Heft 7 Seiten Art.-Nr.: 120 Nachgewiesen in Web of ScienceDimensionsScopus
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